I checked on this on one machine, we did not see any excessive wear, BUT this was on a machine we had built the helical extention as we usually do and did run this helical about 2" over the separator plate we either cut out or remove in order to add teh helical extention. Thus this may prove your theory that extending the helical will avoid this wear area. This was on steep pitch thresher equipped machine R72. I really think though that the steep pitch prevents a lot of the 2nd pass threshing, it does reduce hp therefore it probably will not promote accelerated wear. We will check a few more machines with factory helical to see as we get around to it.